A comprehensive psychometric analysis of autism-spectrum quotient factor models using two large samples: Model recommendations and the influence of divergent traits on total-scale scores.
Drop the AQ total score—use the three-factor model (Social Skill, Patterns/Details, Communication/Mindreading) for clearer results.
01Research in Context
What this study did
The team ran confirmatory factor analysis on the full 50-item Autism-Spectrum Quotient. They tested 11 different models in two large groups of neurotypical adults.
Goal: find the cleanest way to score the AQ and see if the total number means anything.
What they found
A three-factor model won: Social Skill, Patterns/Details, and Communication/Mindreading.
The factors barely talk to each other—some links are negative—so adding them into one total score is “uninterpretable.”
How this fits with other research
Kuenssberg et al. (2014) looked at the 28-item AQ-Short and kept the old two-factor structure. English et al. (2020) now say three factors fit the full form better; the short form may hide that third piece.
Bhat et al. (2023) also told clinicians to drop total scores on the DCD-Q and use five finer subscales. The same “use parts, not the sum” rule keeps popping up across questionnaires.
Haynes et al. (2013) trimmed the SDQ from five factors to three for kids with ID. English et al. (2020) mirror that move—fewer, cleaner factors beat the original long list.
Why it matters
If you give the AQ during intake, stop quoting the total. Report the three subscale scores instead. This small switch gives clearer targets for social-skills training, communication goals, or sensory interventions and keeps you from mislabeling someone because a meaningless total looked high.
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02At a glance
03Original abstract
The Autism-Spectrum Quotient (AQ) is a psychometric scale that is commonly used to assess autistic-like traits and behaviors expressed by neurotypical individuals. A potential strength of the AQ is that it provides subscale scores that are specific to certain dimensions associated with autism such as social difficulty and restricted interests. However, multiple psychometric evaluations of the AQ have led to substantial disagreement as to how many factors exist in the scale, and how these factors are defined. These challenges have been exacerbated by limitations in study designs, such as insufficient sample sizes as well as a reliance on Pearson, rather than polychoric, correlations. In addition, several proposed models of the AQ suggest that some factors are uncorrelated, or negatively correlated, which has ramifications for whether total-scale scores are meaningfully interpretable-an issue not raised by previous work. The aims of the current study were to provide: (a) guidance as to which models of the AQ are viable for research purposes, and (b) evidence as to whether total-scale scores are adequately interpretable for research purposes. We conducted a comprehensive series of confirmatory factor analyses on 11 competing AQ models using two large samples drawn from an undergraduate population (n = 1,702) and the general population (n = 1,280). Psychometric evidence largely supported using the three-factor model described by Russell-Smith et al. [Personality and Individual Differences 51(2), 128-132 (2011)], but did not support the use of total-scale scores. We recommend that researchers consider using AQ subscale scores instead of total-scale scores. Autism Res 2020, 13: 45-60. © 2019 International Society for Autism Research, Wiley Periodicals, Inc. LAY SUMMARY: We examined 11 different ways of scoring subscales in the popular Autism-Spectrum Quotient (AQ) questionnaire in two large samples of participants (i.e., general population and undergraduate students). We found that a three-subscale model that used "Social Skill," "Patterns/Details," and "Communication/Mindreading" subscales was the best way to examine specific types of autistic traits in the AQ. We also found some weak associations between the three subscales-for example, being high on the "Patterns/Details" subscale was not predictive of scores on the other subscales. This means that meaningful interpretation of overall scores on the AQ is limited.
Autism research : official journal of the International Society for Autism Research, 2020 · doi:10.1002/aur.2198